Orthodontic tooth movement is accomplished by fixed and/or removable appliances. One type of appliances that is gaining popularity is orthodontic aligners or clear aligners. Clear aligners are a type of removable appliances used to move the teeth by having the patient wear the said aligner for 1-2 weeks and then switching to another sequential tray where they wear it for 1-2 weeks and so on and so forth.
Clear aligners are fabricated by thermoforming a heat sensitive clear plastic sheet onto a dental model of the teeth. In the aforementioned dental model, the teeth are shifted by a small increment in position and orientation. The concept is that the when the patient wears the plastic trays they will flex and distort and apply force to the teeth forcing them into a new position similar to the dental model used to fabricate the tray. The process is repeated for the number of trays needed to place the teeth in a final position prescribed by a treating doctor or orthodontist. A well-known example is Invisalign®, a polymer-based aligner based on U.S. Pat. No. 5,975,893 (Chishti et al.) and other related patents.
However, there are many areas where aligners are deficient, these areas include and are not limited to:                1) Extraction cases: In extraction cases crowding resolved by extraction of teeth. Usually a premolar is extracted from each quadrant to create enough room to align the remaining teeth. The overall amount of teeth movement is usually quite significantly larger than non-extraction cases. Aligners are usually not suitable for extraction cases and usually orthodontist would use edgewise appliances comprised of braces and arch wires to move the teeth in extraction cases.        2) Cases requiring expansion of the upper and/or lower arches are usually treated using either a specialized expansion device (Quad-helix, bi-helix, active TPA (trans-palatal arch), or hyrax expanders) followed by either edgewise appliance (brackets and arch wires) or aligners. Sometimes expansion can be accomplished using only brackets and heavy arch wires to achieve the expansion.        3) Cases requiring molar uprighting. Uprighting molars requires a great amount of force and cannot be achieved with traditional aligners.        4) Root Movement in general cannot be achieve properly with aligners.        5) Aligners made of plastic cannot exert the amount of force necessary to achieve expansion in the upper and lower arches and are not effective for treatment in the above described areas. Additionally, treatment in these areas requires en-mass movement of distinctive group of teeth, which causes treating using conventional clear aligners difficult, if not impossible.        6) Therefore, there is a need for aligners that overcome the aforementioned short-comings of the clear aligner.        7) Therefore, the embodiments described below address the above-identified issues and needs.        